The present invention relates to an improved stack mold center section carrier for a molding machine.
Stack mold systems for molding articles are known in the prior art. One such stack mold system is shown in U.S. Pat. No. 4,207,051 to Wright. The Wright stack mold system has tiebars which pass through the mold plates, thereby supporting them directly. Removing the molds from the machine requires the tiebars to be withdrawn. This is a time consuming process which requires additional space behind the molding machine's clamp to accommodate the tiebars in their withdrawn positions.
Early stack mold carriers were attachments to the mold center section that supported it in the molding machine and allowed the center section to slide along the machine's tiebars. U.S. Pat. No. 4,408,981 to Brown shows a carrier riding on the lower tiebars. Removal of the mold also required removal of the carriers as they were not attached to the machine. This was an added complication taking more time to change the mold.
U.S. Pat. No. 4,929,166 to DiSimone et al. shows a similar carrier riding between the upper and lower tiebars so that removal of the mold leaves the carrier in place between the tiebars on the machine. The carrier remains attached to the machine by virtue of the half shoe bearings acting on both the upper and lower tiebars. This saved time when a stack mold was removed and replaced with another stack mold, but did not solve the problem when the incoming mold was not a stack mold. In that case, the carriage assembly had to be dismounted from the machine by taking it apart.
There is a need for a mold carrier to which a stack mold can be quickly attached and yet remains safely installed in the machine when the stack mold is removed, and itself can be easily removed from the machine if required.